Chambers for the accelerated weathering and lightfastness testing of components such as fabrics, plastic items, painted surfaces and the like are generally known, for example being shown in Huber et al. U.S. Pat. No. 4,843,893 and Kashima et al. U.S. Pat. No. 4,817,447. Additionally, such testing machines can also test various items as to their resistance against heated air and humidity, or any or all of the above in combination, so that manufacturers can gain data as to the durability of their products on an accelerated basis, to simulate the effects of weathering, heat and the like.
In accordance with this invention, a component testing chamber is provided which is preferably built to large size, to allow the accelerated weathering and lightfastness testing of large components such as automotive dashboards or the like. Since the component testing chamber of this invention is large, preferably a plurality of light emission lamps are used, which light emission lamps may be xenon type lamps, metal halide lamps, fluorescent lamps, ultraviolet lamps, infrared lamps and the like. The term "light" is intended to include frequencies beyond the visible spectrum.
Since the radiation stability testing performed in the testing chamber of this invention needs to be quantitative and reproducible, there is a need for conveniently determining that the intensity of the radiation received by components or samples being tested is that which is expected. By this invention, simple and effective means are provided for the constant irradiance, on a continuing basis, in the testing chamber even though the light emission from various lamps may vary as the lamps age through continued use. Simple means are provided for automatically adjusting the radiation intensity provided to the samples being tested within the chamber of this invention, with the chamber of this invention preferably providing improved uniformity of irradiation in the various positions that samples may occupy within the chamber.